Expert Consensus on the Use of the PRESERFLO™ MicroShunt Device in the Treatment of Glaucoma: A Modified Delphi Panel

Introduction: The implantation of the PRESERFLO (TM) MicroShunt (PMS) device has been shown to significantly lower increased intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG). However, guidelines on best practice for patient selection and pre-/peri-/postoperative care management are lacking. The aim of this modified Delphi panel was to achieve expert consensus on the role of the PMS to treat patients with glaucoma in Europe. Methods: Twelve European glaucoma surgeons experienced with the PMS procedure participated in a three-round modified Delphi panel. A targeted literature review and expert steering committee guided round 1 questionnaire development. Consensus was set at a pre-defined threshold of at least 70% of panellists selecting 'Strongly disagree'/'Disagree' or 'Strongly agree'/'Agree' for six-point Likert scale questions, or at least 70% selecting the same option for multiple-choice questions. Questions not reaching consensus were restated/revised for the next round, following guidance from free-text responses/scoping questions. Results: Consensus was achieved for 60.3% (n = 38/63), 60.0% (n = 18/30), and 100.0% (n = 11/11) of Likert/multiple-choice questions in rounds 1, 2, and 3, respectively. There was agreement that the PMS procedure is effective at reducing IOP in patients with high-tension POAG (greater than 21 mmHg). Although surgical techniques may vary slightly, consensus was reached on several points, including the importance of posterior application of mitomycin C (MMC). Panellists agreed that the PMS postoperative follow-up appointment schedule is reasonably predictable and mostly characterised by fewer visits than with trabeculectomy, particularly in the early phase. Although panellists agreed that combined cataract/PMS surgery and the use of non-MMC wound-healing modulators/antifibrotics during the procedure are possible, further data are needed to determine efficacy. Conclusion: The expert consensus reached in this panel will help inform best practice guidelines in the treatment of patients with glaucoma in Europe. Panellists also highlighted key areas for future research to improve understanding of the PMS in the treatment algorithm of glaucoma.